Someone who is "politically active" due to their narcissistic personality disorder or ill-conceived search for identity and meaning in life. Often caught lecturing others about every single thing that is wrong with society, but not interested in giving up any of their own luxuries or volunteering for any of the actual hard work.

The phrase itself is a reference to Lisa's habit of hijacking social interactions to shame and patronize others with her political and moral absolutism. Best exemplified in the episode 'Bart Star' (Season 9, Episode 6); where Lisa attempts to insert herself to fight for issue after issue, and is thwarted each time with news of morally neutral or even positive solutions to each issue Lisa has raised. In the end, Lisa runs away to cry because rather than truly caring about these issues, Lisa shows us that she only uses them to construct what she thinks is an exciting personal identity in an otherwise dull life.
Phil has become such a Little Lisa Simpson about the environment on social media lately.
Yeah, he sure as fuck burns every ounce of that jet-fuel his parents pay for though.
by HariFontaine February 13, 2019
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